Measurement of Textile Fabrics

ABSTRACT

Apparatus for the measurement of textile fabrics comprising at least one sensor having an associated sensor field. A feed arrangement presents an area of a textile fabric length at the sensor field. The feed arrangement also provides relative movement between the sensor and the textile fabric length to present a sequence of areas of fabric at the sensor field. The sensor is repeatedly operated to provide a colour output representing fabric colour and measured from respective areas of the fabric, as sequentially presented at the sensor field. The feed arrangement operates, each time the sensor provides a colour output, to provide a respective position output representing the position of the sensor relative to the fabric. The feed arrangement and sensor provide a sequence of colour outputs measured from known areas of the fabric, represented by the respective position outputs.

The present invention relates to measurement of textile fabrics. Inparticular, the invention relates to measurement of fabric colour, shadeor the like.

Example embodiments of the present invention provide apparatuscomprising:

-   -   a sensor having an associated sensor field;    -   a feed arrangement operable to present an area of a textile        fabric length at the sensor field;    -   the feed arrangement being further operable to provide relative        movement between the sensor and the textile fabric length to        present a sequence of areas of fabric at the sensor field;    -   the sensor being repeatedly operable to provide a colour output        representing fabric colour and measured from respective areas of        the fabric sequentially presented at the sensor field;    -   and the feed arrangement being operable, each time the sensor        provides a colour output, to provide a respective position        output representing the position of the sensor relative to the        fabric,    -   the feed arrangement and sensor thereby providing a sequence of        colour outputs measured from known areas of the fabric        represented by the respective position outputs.

In this specification, the term “colour” is used to refer to hue, shade,reflectivity or any other parameter of visual appearance which isvisible to the eye.

The feed arrangement may be operable to provide relative movement bymoving the textile fabric length. The feed arrangement may be operableto unroll the textile fabric length from a roll and to present anunrolled area at the sensor field. The textile fabric length may beunrolled from a first roll and rolled to a second roll, the fabric beingpresented at the sensor field while unrolled between the first roll andthe second roll. The sequence of areas presented at the sensor field mayform a line of positions along the textile fabric length.

There may be a plurality of sensors as aforesaid, each having arespective associated sensor field. The plurality of sensors may bearrayed to measure from respective lines of fabric areas, as the textilefabric length moves relative to the sensors. The sensor fields of theplurality of sensors may be arrayed substantially perpendicular to thedirection of relative movement of the textile fabric length and thesensors.

The apparatus may further comprise memory means operable to store thecolour outputs and respective position outputs. The colour outputs andrespective position outputs may be collated to form a datasetrepresenting a map of the textile fabric length. The apparatus mayfurther comprise a visual display means, the visual display means beingoperable to provide a visual representation of the map.

The sensor may provide colour outputs in RGB format. The apparatus mayfurther comprise control means operable to analyse the colour outputs.The control means may be operable to analyse the colour outputs fromeach fabric length to assign an overall colour measurement for eachfabric length. The control means may be operable to determine the rangeof colours represented by the colour outputs for a fabric length. Thecontrol means may be operable to determine if the range of colours isgreater than a permitted maximum range. The control means may beoperable to compare colour outputs to identify matching areas of thefabric by reference to the position outputs. The control means may beoperable to analyse the colour outputs in order to calculate Delta Evalues.

Examples of the invention also provide a method comprising:

-   -   receiving a sequence of colour outputs representing the fabric        colour of a sequence of areas of a textile fabric length;    -   receiving a respective position output for each of the colour        outputs;    -   and determining the position of each of the sequence of areas on        the textile fabric length;    -   thereby providing a sequence of colour outputs measured from        known areas of the fabric represented by the respective position        outputs.

A feed arrangement may be used to provide relative movement between asensor and the textile fabric length to present a sequence of areas offabric at the sensor.

Relative movement may be provided by moving the textile fabric length.The textile fabric length may be unrolled from a roll, an unrolled areabeing presented at the sensor. The textile fabric length may be unrolledfrom a first roll and rolled to a second roll, the fabric beingpresented at the sensor while unrolled between the first roll and thesecond roll. The sequence of areas presented at the sensor may form aline of positions along the textile fabric length.

There may be a plurality of sensors. The plurality of sensors may bearrayed to measure from respective lines of fabric areas, as the textilefabric length moves relative to the sensors. The sensor fields of theplurality of sensors may be arrayed substantially perpendicular to thedirection of relative movement of the textile fabric length and thesensors.

The colour outputs and respective position outputs may be stored. Thecolour outputs and respective position outputs may be collated to form adataset representing a map of the textile fabric length. A visualdisplay means may be used to provide a visual representation of the map.

The colour outputs may be analysed. The colour outputs from each fabriclength are analysed to assign an overall colour measurement for eachfabric length. The colour outputs may be analysed to determine the rangeof colours represented by the colour outputs for a fabric length. Themethod may determine if the range of colours is greater than a permittedmaximum range. The method may compare colour outputs to identifymatching areas of the fabric by reference to the position outputs. Themethod may analyse the colour outputs in order to calculate Delta Evalues.

The invention also provides software which, when installed on a computersystem, is operable to perform the whole or any part of the precedingmethod. The invention also provides a computer readable medium havingmachine-readable instructions recorded thereon and representing softwareas aforesaid.

In another aspect, examples of the invention provide a batch of fabricpanels cut from fabric lengths, the fabric panels being matched inaccordance with colour outputs and position outputs obtained by means ofthe apparatus set out above, or in accordance with the method set outabove.

Examples of the present invention will now be described in more detail,by way of example only, and with reference to the accompanying drawings,in which:

FIG. 1 is a schematic side view of an example apparatus for use inimplementing the invention;

FIGS. 2 and 3 are schematic views of the apparatus of FIG. 1; at thelines 2-2 and 3-3 in FIG. 1;

FIG. 4 is an enlarged schematic view of a sensor;

FIG. 5 illustrates a display of the device; and

FIG. 6 illustrates an example method of the invention.

The drawings illustrate apparatus 10 comprising at least one sensor 12having an associated sensor field indicated generally at 14. A feedarrangement 16 is operable to present an area 17 of a textile fabriclength 18 at the sensor field 14. The feed arrangement 16 also providesrelative movement between the sensor 12 and the textile fabric length 18to present a sequence of areas 17 of fabric at the sensor field 14. Thesensor 12 is repeatedly operated, as will be described, to provide acolour output representing fabric colour and measured from respectiveareas 17 of the fabric, as sequentially presented at the sensor field14. The feed arrangement 16 operates, each time the sensor 12 provides acolour output, to provide a respective position output representing theposition of the sensor 12 relative to the fabric 18. The feedarrangement 16 and sensor 12 thereby providing a sequence of colouroutputs measured from known areas 17 of the fabric 18, represented bythe respective position outputs.

In more detail, the apparatus 10 has an unrolling station 20 forreceiving a roll 22 of textile fabric. A rolling station 24 is providedfor receiving an initially empty roll 26. The apparatus 10 has a drivemechanism illustrated schematically at 28 and defines a path 30 for aweb of fabric 18 to pass from the roll 22, along the path 30, to theempty roll 26. Accordingly, the feed arrangement 16, including the drivemechanism 28, provides relative movement between the textile fabriclength 18 and the sensor 12, by moving the textile fabric length 18.Alternatively, the sensor 12 could be moved to scan the surface of thelength 18, but the extreme length of fabric rolls used commercially(which may be up to 5 km in length) makes it more practical to move thefabric past the sensor 12. A combination of movement of the sensor 12and the fabric length 18 could be used. As the textile fabric lengthmoves along the path 30 from the roll 22 to the roll 26, a line ofpositions along the textile fabric length 18 will be sequentiallypresented to the sensor 12.

FIGS. 2 and 3 illustrate the textile fabric length 18 as it moves alongthe path 30 of the apparatus 10. The fabric length 18 moves past thesensor 12 which, in this example, includes three sensor heads 12. Adifferent number of sensor heads 12 could be used. It is envisaged thatas many as thirty sensor heads 12 could be used together. Each sensorhead 12 has a respective sensor field 14 associated with it, as will bedescribed. The sensor heads 12 are arrayed, in this example, in a linewhich is generally perpendicular with the direction of movement of thetextile fabric length 18 relative to the sensor heads 12, this directionbeing indicated in FIG. 2 by an arrow 34. As the fabric length 18 movespast the sensor heads 12, a line of positions 36 passes each sensor head12. The positions 36 are diagrammatically illustrated in FIG. 2 asoverlapping circular regions. In the region 38, before the fabric 18reaches the sensor heads 12, each position 36 is plain, for reasonswhich will become apparent. In the region 40, after the fabric 18 haspassed the sensor head 12, each position 36 is shaded, for reasons whichwill become apparent.

It can be seen from FIG. 2 that the sensor heads 12 define respectivelines of positions 36 which run parallel along the length of the fabriclength 18. As the textile fabric length 18 is fully unrolled from theroll 22 to the empty roll 26, the lines of positions 36 will extendalong the whole length of the fabric length 18.

One of the sensor heads 12 is illustrated in more detail in FIG. 4. Thesensor head 12 includes a transducer 42 housed within a shroud 44 toreduce the effects of ambient light, reflections etc. A light source 46is provided to create reliable, consistent lighting in the vicinity ofthe head 12. Control electronics 48 or other apparatus associated withthe head 12 may also be housed within the shroud 44, which may act as areflector to cast the output of the light source 46 onto the textilefabric length 18. The transducer 42 has a viewing angle 50, illustratedby broken lines in FIG. 4, which therefore defines a sensor field 14 atthe fabric length 18. As the textile fabric length 18 moves past thesensor head 12, a sequence of areas of fabric will be presented to thesensor head 12.

The transducer 42 of each sensor head 12 is able to take a measurementfrom the corresponding sensor field 14, representing the fabric colourseen by the transducer 42 at the field 14. Suitable transducers formeasuring colour are known in themselves and may report in a number ofstandard formats. One format is known as RGB format, and is used in thisexample. RGB format allows other formats to be calculated from it, ifrequired or desired.

The fabric colour is therefore measured without damaging the fabric.

The apparatus 10 also includes a position encoder 52 which detects themovement of the textile fabric length 18 along the path 30. Accordingly,the encoder 52 can report the length of fabric which has passed. Thisposition, together with the relative positions of the encoder 52 and thesensor heads 12 allows the determination of the current position of eachof the sensor fields 14 on the textile fabric length 18. That is, eachtime a sensor head 12 provides a colour output representing fabriccolour, measured from the respective sensor field 14, a position outputcan be taken from the position encoder 52. This links the colour outputto a particular position on the fabric length 18, as has just beenexplained.

It is for this reason that the regions 38, prior to the sensor 12, areplain, because no information is yet known about fabric colour in theregion 38. However, the regions 40 have passed the sensor 12, colouroutputs have been obtained from the sensor heads 12 and position outputshave been obtained from the position encoder 52, so that the colour ofthe regions 40, and their position, are both now known and are thereforeillustrated in FIG. 2 by the simple diagrammatic schema of dark areas,light areas and shaded areas, to indicate three different colours. Itshould be understood that in a practical example, using conventionalcolour measurement techniques, many more than three discrete colourstates would be identified.

The colour outputs from the sensor heads 12, and the position outputsfrom the position encoder 52 are all fed to a control arrangement 54which may, for example, be implemented by means of appropriate softwarerunning on a general purpose computer. For the purpose of understandingthe present invention, it is sufficient to explain that the controlarrangement 54 includes a data processing element 56, associated memory58 and a visual display unit 60. In this example, all colour outputs andrespective position outputs received from the sensor heads 12 andposition encoder 52 are stored in the memory 58 of the data-processingelement 56. Further data-processing can then take place. In particular,the correspondence between each colour output and its respectiveposition output allows the data to be collated to form a dataset whichrepresents a map of the colour of the textile fabric length 18. Thismap, as it is being formed, is indicated in FIG. 2 by the appearance ofthe regions 40.

The map may be presented to the user by means of the visual display unit60, under control from the data-processing element 56. FIG. 5illustrates an example of a display. The lower region 62 shows a mapcollated from the colour outputs and respective position outputs. Themap may show the detected colours, or be in any other appropriate formatto provide the required information to the user. For example, thedata-processing element 56 may analyse the colour outputs and presentthe results of the analysis in the region 62, rather than presenting theactual colours detected. The analysis may determine any areas whosecolour varies from a target colour by more than a maximum allowableamount. Variation may be measured by a conventional colour measurementtechnique. In this example, variation is calculated as a Delta E valuecalculated by the data-processing element 56 from RGB outputs from thesensor heads 12. Delta E values measure the variance of a colour orshade from the intended value. A Delta E value greater than unityindicates a difference which is visible to the human eye. A Delta Evalue less than unity indicates a difference which is not visible to thehuman eye.

Alternatively, the analysis may compare colour outputs from variousdifferent areas across the fabric length 18 in other ways, to identifythose areas which provide an acceptably close visual match (for garmentmanufacture, for example).

Accordingly, the map shown in the region 62 may indicate areas whichmatch or which lie outside the permitted colour range for the particularroll, rather than showing the actual colour detected.

Additional information can be provided in the upper region 64 of thedisplay 60, such as information identifying the roll of fabric, itsmanufacturer, intended colour etc. Other fields may include an averageDelta E value 66 for the whole of the textile fabric length 18, and anindication 68 of bandwidth (variation) of Delta E values across thelength 18.

Analysis of the colour outputs and position outputs may be executedlocally, at the apparatus 10, or remotely. In the case of remoteanalysis, this may take place within the same premises, or the data maybe transmitted by any appropriate medium, including the Internet, foranalysis elsewhere.

FIG. 6 schematically represents a complete process for manufacturingitems of clothing from textile fabric, to provide an example of themanner in which examples of the present invention may be used.

In FIG. 6, a batch of textile fabric lengths 18 have been received froma manufacturer. These are all intended to have a particular intendedcolour, but in practice, there will be colour variations betweenlengths, and within a single length. The lengths 18 are schematicallyillustrated as bars of block shading or line shading, or unshaded toindicate different colours. Again, only three alternatives are shown,solely for illustrative purposes. In a practical example, the fabriclengths 18 will usually be rolls of fabric.

Each of the textile fabric lengths 18 is first inspected by passing theroll through the apparatus 10, described above. In this first example,this allows a Delta E value to be measured for each length 18,representing the average variance of the colour of that length from theintended colour for the roll. Accordingly, the lengths 18 can be sorted(indicated at 70) to group them into matching colour groups. That is,the average variance of two rolls may indicate that the fabric of thosetwo rolls will match tolerably for garment manufacture, even thoughthose rolls will not acceptably match with other rolls of the batch. Therolls are allocated to groups on this basis. Each length 18 can then becut into panels 72 from which garments can be made. The resulting panels72 indicated in FIG. 6 are kept in groups corresponding with the groupsof rolls from which they were cut and thus, they remain groupedaccording to their colour. This grouping readily allows garments 74 tobe constructed from groups of matching panels 72, so that the resultinggarments 74 will pass quality control checks in relation to colourmatch, even though there will be variation between garments made fromdifferent groups. Thus, it is expected that by grouping panels 72 onlyfrom lengths 18 which match each other, to create groups of panels 72which match each other, the risk of creating a single garment 74 fromseveral panels 72 which do not match each other can be significantlyreduced, so that the rejection rate of finished garments 74 can also besignificantly reduced.

In the example just described, many colour measurements made across andalong each roll are used to assign an overall colour measurement to thatroll. It is the overall measurement which then determines the groupingof rolls, and hence the grouping of garment panels.

In a further example, the apparatus 10 is used to form a map of eachlength 18, and the lengths 18 are then cut into panels 72 with dueregard to the colours indicated by the maps. Thus, a length 18 which hascolour variation within it, can be used to contribute panels 72 todifferent groups. That is, panels cut from within the single length 18are grouped with other panels of the same colour variation cut from thesame length 18 or from another length 18. Again, it is envisaged that bygrouping panels 72 according to their colour, and facilitating thisgrouping by forming the map by operation of the apparatus 10, there willbe a significantly reduced risk of garments 74 being formed from panels72 which do not match each other.

In this second example panels are grouped according to the colour of thepanel itself, regardless of colour variation elsewhere on the same roll.

We envisage that in many practical situations, it will be possible toproduce garments of adequate quality even if some of the lengths 18 donot match each other, or do not have consistent colour along theirlength. This will result in garments 74 which vary in colour fromgarment to garment, but which have acceptable panel matching within eachgarment. However, in the event that any length 18 is found to beunacceptably variant from the intended colour, as detected by theapparatus 10, the whole length 18 or the detected part of the length 18can be rejected.

Wastage arising from rejection of finished garments is thereforeexpected to be significantly reduced.

Many variations and modifications may be made to the apparatus describedabove, without departing from the scope of the present invention. Forexample, many technologies and techniques could be used for the sensorsand for processing, using and displaying the data.

Whilst endeavouring in the foregoing specification to draw attention tothose features of the invention believed to be of particular importanceit should be understood that the Applicant claims protection in respectof any patentable feature or combination of features hereinbeforereferred to and/or shown in the drawings whether or not particularemphasis has been placed thereon.

1. Apparatus comprising: a sensor having an associated sensor field; afeed arrangement operable to present an area of a textile fabric lengthat the sensor field; the feed arrangement being further operable toprovide relative movement between the sensor and the textile fabriclength to present a sequence of areas of fabric at the sensor field; thesensor being repeatedly operable to provide a colour output representingfabric colour and measured from respective areas of the fabricsequentially presented at the sensor field; and the feed arrangementbeing operable, each time the sensor provides a colour output, toprovide a respective position output representing the position of thesensor relative to the fabric, the feed arrangement and sensor therebyproviding a sequence of colour outputs measured from known areas of thefabric represented by the respective position outputs.
 2. Apparatusaccording to claim 1, wherein the feed arrangement is operable toprovide relative movement by moving the textile fabric length. 3.Apparatus according to claim 1, wherein the feed arrangement is operableto unroll the textile fabric length from a roll and to present anunrolled area at the sensor field.
 4. Apparatus according to claim 1,wherein the textile fabric length is unrolled from a first roll androlled to a second roll, the fabric being presented at the sensor fieldwhile unrolled between the first roll and the second roll.
 5. Apparatusaccording to claim 1, wherein the sequence of areas presented at thesensor field form a line of positions along the textile fabric length.6. Apparatus according to claim 1, wherein there is a plurality ofsensors as aforesaid, each having a respective associated sensor field.7. Apparatus according to claim 6, wherein the plurality of sensors isarrayed to measure from respective lines of fabric areas, as the textilefabric length moves relative to the sensors.
 8. Apparatus according toclaim 6, wherein the sensor fields of the plurality of sensors isarrayed substantially perpendicular to the direction of relativemovement of the textile fabric length and the sensors.
 9. Apparatusaccording to claim 1, wherein the apparatus further comprises memorymeans operable to store the colour outputs and respective positionoutputs.
 10. Apparatus according to claim 1, wherein the colour outputsand respective position outputs are collated to form a datasetrepresenting a map of the textile fabric length.
 11. Apparatus accordingto claim 10, wherein the apparatus further comprises a visual displaymeans, the visual display means being operable to provide a visualrepresentation of the map.
 12. Apparatus according to claim 1, whereinthe sensor provides colour outputs in RGB format.
 13. Apparatusaccording to claim 1, wherein the apparatus further comprises controlmeans operable to analyse the colour outputs.
 14. Apparatus according toclaim 13, wherein the control means is operable to analyse the colouroutputs from each fabric length to assign an overall colour measurementfor each fabric length.
 15. Apparatus according to claim 13, wherein thecontrol means is operable to determine the range of colours representedby the colour outputs for a fabric length.
 16. Apparatus according toclaim 15, wherein the control means is operable to determine if therange of colours is greater than a permitted maximum range. 17.Apparatus according to claim 13, wherein the control means is operableto compare colour outputs to identify matching areas of the fabric byreference to the position outputs.
 18. Apparatus according to claim 13,wherein the control means is operable to analyse the colour outputs inorder to calculate Delta E values.
 19. (canceled)
 20. A methodcomprising: receiving a sequence of colour outputs representing thefabric colour of a sequence of areas of a textile fabric length;receiving a respective position output for each of the colour outputs;and determining the position of each of the sequence of areas on thetextile fabric length; thereby providing a sequence of colour outputsmeasured from known areas of the fabric represented by the respectiveposition outputs.
 21. A method according to claim 20, wherein a feedarrangement is used to provide relative movement between a sensor andthe textile fabric length to present a sequence of areas of fabric atthe sensor.
 22. A method according to claim 21, wherein relativemovement is provided by moving the textile fabric length.
 23. A methodaccording to claim 21, wherein the textile fabric length is unrolledfrom a roll, an unrolled area being presented at the sensor.
 24. Amethod according to claim 21, wherein the textile fabric length isunrolled from a first roll and rolled to a second roll, the fabric beingpresented at the sensor while unrolled between the first roll and thesecond roll.
 25. A method according to claim 21, wherein the sequence ofareas presented at the sensor forms a line of positions along thetextile fabric length.
 26. A method according to claim 21, wherein thereis a plurality of sensors.
 27. A method according to claim 26, whereinthe plurality of sensors is arrayed to measure from respective lines offabric areas, as the textile fabric length moves relative to thesensors.
 28. A method according to claim 26, wherein the sensor fieldsof the plurality of sensors are arrayed substantially perpendicular tothe direction of relative movement of the textile fabric length and thesensors.
 29. A method according to claim 20, wherein the colour outputsand respective position outputs are stored.
 30. A method according toclaim 20, wherein the colour outputs and respective position outputs arecollated to form a dataset representing a map of the textile fabriclength.
 31. A method according to claim 30, wherein a visual displaymeans is used to provide a visual representation of the map.
 32. Amethod according to claim 20, wherein the colour outputs are analysed.33. A method according to claim 20, wherein the colour outputs from eachfabric length are analysed to assign an overall colour measurement foreach fabric length.
 34. A method according to claim 20, wherein thecolour outputs are analysed to determine the range of coloursrepresented by the colour outputs for a fabric length.
 35. A methodaccording to claim 34, wherein the method determines if the range ofcolours is greater than a permitted maximum range.
 36. A methodaccording to claim 20, wherein the method compares colour outputs toidentify matching areas of the fabric by reference to the positionoutputs.
 37. A method according to claim 20, wherein the method analysesthe colour outputs in order to calculate Delta E values.
 38. Softwarewhich, when installed on a computer system, is operable to perform thewhole or any part of the method of claim
 20. 39. A computer readablemedium having machine-readable instructions recorded thereon andrepresenting software according to claim
 38. 40. (canceled)
 41. A batchof fabric panels cut from fabric lengths, the fabric panels beingmatched in accordance with colour outputs and position outputs obtainedby means of the apparatus of claim
 1. 42. A batch of fabric panels cutfrom fabric lengths, the fabric panels being matched in accordance withcolour outputs and position outputs obtained in accordance with themethod of claim
 20. 43-44. (canceled)